Pacific abalone, Haliotis discus hannai is a high commercial seafood in South-East Asia. The aim of the present study was to determine effects of cryopreservation on gene expression and post thaw sperm quality of Pacific abalone, H. discus hannai. Two ions, Na+ (459.1 ± 3.1 mM) and Cl- (515.9 ± 1.1 mM), were predominant in the seminal plasma (pH: 6.8 ± 0.1; osmolarity: 1126 ± 3 mOsmL-1). Cryopreservation reduced mRNA expression levels of protein kinase A (PKA-C) and heat shock proteins (HSP70 and HSP90) genes in sperm. Fluorescent technique was used to compare morphological defects, acrosome integrity (AI), plasma membrane integrity (PMI), mitochondrial membrane potential (MMP), and DNA integrity of sperm cryopreserved with five different cryopreservation solutions (8% Me2SO, 8% EG, 6% PG, 2% GLY, and 2% MeOH). Droplet in tail and coiled tail defects were not observed for sperm cryopreserved with 8% Me2SO or 2% GLY. Sperm cryopreserved with 8% Me2SO showed improved DNA integrity and lower cryodamage than sperm cryopreserved with other cryoprotectants. Sperm to egg ratio of 10000:1 was found to be the most suitable ratio for in vitro fertilization among different ratios tested. The fertilization rate of sperm cryopreserved with 8% Me2SO was not significantly (p > 0.05) different from that of sperm cryopreserved with 2% GLY. DNA fragmentation showed strongly negative relationships with sperm quality parameters. Sperm cryopreserved with 8% Me2SO showed higher post thaw quality and mRNA expression of sperm motility associated gene than those cryopreserved with other cryoprotectants. The present research suggests to use 8% Me2SO for cryopreservation of Pacific abalone sperm as well as for hatchery production.

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Effects of Cryopreservation on Gene Expression and Post Thaw Sperm Quality of Pacific Abalone, Haliotis discus hannai

Metolachlor adsorption using walnut shell biochar modified by soil minerals.

Microbial electrochemical bioremediation of petroleum hydrocarbons (PHCs) pollution: Recent advances and outlook

Impact of ocean acidification on the intestinal microflora of the Pacific oyster Crassostrea gigas

Effects of pyrolysis temperature and aging treatment on the adsorption of Cd2+ and Zn2+ by coffee grounds biochar.

This study investigates the changes in the drought frequency in 2070–2099 relative to 1970–1999, due to the mean and shape changes of the probability density function (PDF) of the self-calibrated Palmer Drought Severity Index (PDSI), using CMIP5 multi-model historical simulations and projections under the RCP4.5 scenario. For severe droughts defined with PDSIs less than the 10th percentile, it is shown that over 41% of the global land, the increase in the severe drought frequency due to the shape change exacerbates the increase due to the mean change. Over 28% of the global land, the decrease in the drought frequency due to the shape change partially offsets the increase due to the mean change. Over 31% of the global land, the drought frequency increases due to the shape changes, but decreases due to the mean changes. The severe drought frequency due to both PDSI PDF mean and shape changes increases over almost the entire global land. We show that the PDSI standard deviation change is mainly determined by the mean precipitation change, while the PDSI mean change is determined by both mean precipitation and potential evapotranspiration changes. In particular, the PDSI standard deviation increases with the increase in mean precipitation which broadens the PDSI PDF, and thus enhances the severe drought frequency, and vice versa. On the other hand, the PDSI mean decreases with the decrease (increase) in mean precipitation (mean potential evapotranspiration). The difference in the attribution of drought frequency changes to the mean and shape changes over different regions can thus be largely explained by the mean precipitation and potential evapotranspiration changes. We also examine the moderate droughts defined with PDSIs between 10th and 20th percentiles in this study. For the moderate drought frequency, the spatial pattern of its changes due to the PDSI mean changes is similar to that of severe drought but with much smaller magnitudes, while its change in the spatial pattern due to the shape changes differs from severe drought with no significant changes. The moderate drought frequency due to both PDSI PDF mean and shape changes increases over 71% of the global land but decreases over 29% of the land.

/pdf/future-changes-in-drought-frequency-due-to-changes-in-the-34tb8r61.pdf

Future Changes in Drought Frequency Due To Changes in the Mean and Shape of the PDSI Probability Density Function Under RCP4.5 Scenario

The tissues of marine invertebrates are colonized by species-rich microbial communities. The dysbiosis of host’s microbiota is tightly associated with the invertebrate diseases. Yesso scallop (Patinopecten yessoensis), one of the most important maricultured scallops in northern China, has recently suffered massive summer mortalities, which causes huge production losses. The knowledge about the interactions between the Yesso scallop and its microbiota is important to develop the strategy for the disease prevention and control. In the present study, the bacterial communities in hemolymph, intestine, mantle and adductor muscle were compared between the healthy and diseased Yesso scallop based on the high-throughput sequencing of 16S rRNA gene. The results indicated obvious difference of the composition rather than the diversity of the bacterial communities between the healthy and diseased Yesso scallop. Vibrio, Francisella and Photobacterium were found to overgrow and dominate in the mantle, adductor muscle and intestine of the diseased scallops, respectively. The prediction of bacterial community metagenomes and the variations of KEGG pathways revealed that the proportions of the pathways related with neurodegenerative diseases and carbohydrate metabolism both increased significantly in the mantle and hemolymph of the diseased scallops. The abundance of the metabolism pathways including carbohydrate metabolism, lipid metabolism and amino acid metabolism decreased significantly in the intestine of diseased scallops. The results suggested that the changes of bacterial communities might be closely associated with the Yesso scallop’s disease, which was helpful for further investigation of the pathogenesis as well as prevention and control of the disease in Yesso scallop.

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The differences of bacterial communities in the tissues between healthy and diseased Yesso scallop (Patinopecten yessoensis).

Protein kinase A plays a central role in the regulation of sperm motility from echinoderms to mammals, but the information about its regulatory role in molluscs is very limited. In this study, a protein kinase A catalytic subunit (designated as HdPKA‐C) was identified from Pacific abalone Haliotis discus hannai. The open reading frame of HdPKA‐C was of 1,077 bp, encoding a peptide of 358 amino acids with a typical protein kinase domain. HdPKA‐C shared 82%–87% sequence similarities with other PKA‐Cs, and it was clustered first with gastropod PKA‐Cs in the phylogenetic tree. The mRNA of HdPKA‐C was constitutively expressed in examined tissues, with the highest level detected in hepatopancreas. The phosphorylated form of HdPKA‐C (p‐HdPKA‐C) was localized at the acrosome, connecting piece and flagellum of spermatozoa with variable intensity. Its phosphorylated substrates were also detected in these regions with much lower intensity at the connecting piece. The inhibition of HdPKA‐C activity with H‐89 led to a significant reduction in the percentage of motile sperm and sperm velocities. p‐HdPKA‐C was detected by Western blot in strip‐spawned sperm, naturally spawned sperm and H‐89‐treated sperm with almost the same intensity. The intensity of p‐HdPKA‐C substrates in naturally spawned sperm was higher than that in strip‐spawned sperm, and it was roughly the same as that in H‐89‐treated sperm except for two bands at 50 and 60 kDa. These results collectively indicated that HdPKA‐C played an important role in the regulation of abalone sperm motility by altering its substrates phosphorylation.

Qiang Fu

Papers

Effects of pyrolysis temperature and aging treatment on the adsorption of Cd2+ and Zn2+ by coffee grounds biochar.

Impact of ocean acidification on the intestinal microflora of the Pacific oyster Crassostrea gigas

Future Changes in Drought Frequency Due To Changes in the Mean and Shape of the PDSI Probability Density Function Under RCP4.5 Scenario

The differences of bacterial communities in the tissues between healthy and diseased Yesso scallop (Patinopecten yessoensis).

The effects of protein kinase A catalytic subunit on sperm motility regulation in Pacific abalone Haliotis discus hannai